As far back as the eighth century, what’s now known as the Castile region of Spain was famous for this olive oil-based product. Supposedly it was beloved by Spanish royalty and sought out by other European nobles. Today you needn’t be a prince to enjoy Castile soap. Just buy yourself a bottle and mix ¼ cup in 2 gallons of warm water for mopping linoleum floors; add 2 drops to 1 quart of warm water and use a barely moistened sponge to wipe down fabric upholstery; or add a squirt to a cup of hot water and apply to the stovetop, the burners, and the vent hood to cut through accumulated grease.
To buy: $19, amazon.com.